My laptop Asus Rog Strix G531GT has been experience an issue with something. When I turn it on, the fan and HDD runs also the led is lit up. But no boot sound or screen (not always, but sometimes). But when I connect external monitor I can see the screen and signup window. I tried changing the project modes and also did reset windows. But nothing seems to resolve the issues. But when I restart or shutdown and turn on again, the laptop screen comes back with boot sound. Couple of months back, Asus changed the motherboard of my laptop under warranty because of an issue with sound output. This problem of not turning on the screen started few weeks after changing motherboard? Could it be a faulty motherboard or is it any issue with RAM or monitor itself? If monitor is faulty, then what can be the reason for no boot up sound?
Well this issuse may be happening becuase you may have the problem in graphics driver or a problem with the LCD display back light. As you say that you have change the motherboard of so that can be one of the issuse of not turning on the screen and for the sound output issuse you should check the drvier update or driver which are related to the sound of your laptop. You can update your system driver as well this may also help in solving the issuse which your are facing.
I think it started after a driver update. But what confuses me is that, this doesn't happen all the time. Most of the times the laptop turns on normally. But few times, especially the first boot in a day, it won't start. Either the monitor and sound won't be there (in that case I plug in my second monitor and restart the laptop) or only the fan and hdd runs.
I have updated the driver from intel's website. Let's me see, if this fixes. I will update here